The present invention relates to compositions for protective coatings, particularly, protective coatings for metallic surfaces. More particularly, the present invention relates to coating compositions having anti-corrosive and anti-abrasive properties and which are sound deadeners.
Coating compositions find a wide field of applications in the automotive industry, especially for coating surfaces underneath automobiles which are subjected to rough contact with materials such as gravel, sand and dust. Such compositions are also widely used in the appliance industry, especially for sound proofing and protecting against corrosion of internal surfaces of domestic appliances such as washing machines, refrigerators, etc.
Compositions for coating surfaces and having anticorrosive, anti-abrasive and sound deadening properties are well known in the prior art. However, these compositions must fulfill diverse conditions such as resistance to widely varying temperatures, good adhesion to the metallic substrates, age stability and economic suitability. While the known compositions are reasonably satisfactory for many uses, many of such compositions are limited in usage since they do not meet all of the necessary criteria.
The compositions generally used comprise bitumen solutions and fillers, as described in British patent Nos. 1,101,799, or in Canadian patent 794,751. Such products have good anti-corrosive and sound deadening properties and are inexpensive, but they are unsatisfactory with regard to antiabrasion, cohesion and resistance to low temperatures. Other compositions, more particularly used as underbody coatings, are based on polyvinyl plastisols. Such products have good anti-corrosive and anti-abrasive characteristics, but are rather expensive, and have poor storage stability and further, cause considerable wear to the appliances to which they are applied.
An object of the present invention is to provide a new and improved composition for protective coatings, particularly suitable for metallic surfaces, having an optimum combination of the required coating properties while being economically satisfactory.
A further object of the present invention is to provide a new and improved coating composition which may be easily applied by conventional spraying systems.